Conventionally, plastic molded components having light weight, high strength, and high durability have often been used for interior and exterior parts of automobiles, such as garnishes, grilles, instrument panels, trims, bezels, covers, and lamp housings. In the case in which two or more kinds of textures (metal, wood grain) or color tones are represented by a single plastic molded component, although post-treatment such as painting or plating can be performed, a molding method, such as insert molding and two-color molding utilizing, a molding process is advantageous in terms of manufacturing cost and durability. As the two-color molding, there are available a rotary system (JP45-6947B) in which after primary molding, a die or a molding section is rotated to perform secondary molding, and a core back system (JP3203870B, JP3267230B, JP2000-210978A, JP11-207782A) in which after primary molding has been performed by dividing the interior of the molding section by a slide core, secondary molding is performed by retracting the slide core.
In these molding methods, parts must be integrated mutually in terms of shape, or they must be integrated by the mutual adhesive properties of resin materials. For example, in the case of two-color molding for multi-coloring, usually, it is advantageous to secure joint strength by using the same kind of resin materials. However, in some cases, the integral shape of a boundary part cannot be set due to restrictions as to shape of the molded component, or the joint area cannot be secured sufficiently. Furthermore, in some cases, each part places demands on the material, for example, demands on function or demands on cost, so that a combination of dissimilar materials having low mutual adhesive properties is desired. In such cases, it is difficult to perform two-color molding.
On the other hand, in some cases, film insert molding is performed to decorate the member surface (JP2000-52416A, JP2003-220623A, JP2000-263599A). In the film insert molding, by selecting raw materials of layers of the film having a multilayer structure, desired adhesive properties are obtained. For example, a film having a three-layer structure, in which a transparent film is decorated by printing or metal deposition, a weather-resistant protective film is adhered to the top surface side, and a film for joining is adhered to the back surface side, is used and insert-molded, by which the film is integrated with a resin material serving as a base.
The above-mentioned insert film must be preformed to be set in a die. Also, an edge end portion appearing in appearance after molding must be trimmed. However, unlike the ordinary insert molding, the film insert molding method has a problem in that the trimming line is easily shifted by the flow of resin and the thermal shrinkage of film itself at the time of molding. Furthermore, since deposited metal in the film middle layer is exposed on the trimming line, in the case in which the molded component is used for an exterior part of an automobile, there arises a problem in that the exposed deposited metal may cause corrosion or peeling. For these reasons, in the film insert molding, the trimming line is not set in a design surface. In general, the whole of the member is covered with the insert film, including the case in which the textures or color tones are changed over in the decorating layer of insert film. Unlike the ordinary inert molding and the two-color molding, the film insert molding has not been used to produce two or more kinds of textures or color tones by a single plastic molded component.